50T35-743 Integrated Furnace Control INSTALLATION INSTUCTIONS FAILUE TO EAD AND FOLLO ALL INSTUCTIONS CAEFULLY BEFOE INSTALLIN O OPEATIN THIS CONTOL COULD CAUSE PESONAL INJUY AND/O POPETY DAMAE. DESCIPTION The 50T35-743 is an automatic gas interrupted ignition control that employs a microprocessor to continually monitor, analyze, and control the proper operation of the gas burner, inducer, and fan. Signals interpreted during continual surveillance of the thermostat and flame sensing element initiate automatic ignition of the burner, sensing of the flame, and system shut-off during normal operation. This control incorporates system fault analysis for quick gas flow shut-off, coupled with automatic ignition retry upon sensing a fault correction. It is designed as a replacement for the following controls: Model eplaces hite-odgers 50T35-743 oodman B18099-06 oodman B18099-08 oodman B18099-10 oodman B18099-13 PECAUTIONS Installation should be done by a qualified heating and air conditioning contractor or licensed electrician. If in doubt about whether your wiring is millivolt, line, or low voltage, have it inspected by a qualified heating and air conditioning contractor or licensed electrician. Do not exceed the specification ratings. All wiring must conform to local and national electrical codes and ordinances. This control is a precision instrument, and should be handled carefully. ough handling or distorting components could cause the control to malfunction. Following installation or replacement, follow manufacturer s recommended installation/service instructions to ensure proper operation. CAUTION Do not short out terminals on gas valve or primary control. Short or incorrect wiring may damage the thermostat. Index Page Description 1 Precautions 1 Specifications 2 Installation 3 Typical System iring 5 ANIN Failure to comply with the following warnings could result in personal injury or property damage. FIE HAZAD Do not exceed the specified voltage. Protect the control from direct contact with water (dripping, spraying, rain, etc.). If the control has been in direct contact with water, replace the control. Label all wires before disconnection when servicing controls. iring errors can cause improper and dangerous operation. oute and secure wiring away from flame. SHOCK HAZAD Disconnect electric power before servicing. Ensure proper earth grounding of appliance. Ensure proper connection of line neutral and line hot wires. EXPLOSION HAZAD Shut off main gas to appliance until installation is complete. www.white-rodgers.com PAT NO. 37-6533B eplaces 37-6533A 0614
SPECIFICATIONS ELECTICAL ATINS [@ 77 F (25 C)]: Input Voltage: 25 VAC 60 Hz Max. Input Current @ 25 VAC: 0.5 amp + Main Value Load elay Load atings: Valve elay: 1.5 amp @ 24 VAC 60 Hz 0.6 pf Ignitor elay: 5.0 amp @ 120 VAC 60 Hz (resistive) Circulator elay: 11 FLA 26.0 LA @ 120 VAC Humidifier Load ating: 0.5A @ 24 VAC 1.0A @ 120 VAC Electronic Air Cleaner Load ating: 1A @ 120 VAC Flame Current equirements: Minimum current to insure flame detection: 1 µa DC* Maximum current for non-detection: 0.1 µa DC* Maximum allowable leakage resistance: 100 M ohms *Measured with a DC microammeter in the flame probe lead OPEATIN TEMPEATUE ANE: -40 to 175 F (-40 to 80 C) HUMIDITY ANE: 5% to 93% relative humidity (non-condensing) MOUNTIN: Surface mount multipoise Timing Specs: Flame Establishing Time: Flame Failure esponse Time: maximum 0.8 sec 2.0 sec ases Approved: Natural, Manufactured, Mixed, Liquified Petroleum, and LP as Air Mixtures are all approved for use. Timing Specifications (All times are in seconds, unless noted otherwise) Timing Specification Description 50T35-743 Pre-Purge Initial delay between thermostat contact closure and trial for ignition. 15 Initial Ignitor arm-up Duration of ignitor warm-up time on the first 64 attempts. 15 etry Ignitor arm-up Duration of ignitor warm-up time if the control retries. 20 Ignition Activation Period The period of time between energizing the main gas valve and deactivation of 5 the ignition means prior to the lockout time. Trial for Ignition Period during which the valve and ignition source is activated, attempting to 7 ignite gas at the burner. etries Additional ignition attempts if the original ignition attempt is unsuccessful. 2 times Valve Sequence Period Valve sequence period is the cumulative total amount of time that the gas valve 12 is energized before entering lockout. Inter-Purge Period between trials for ignition when both the gas valve and ignition source 30 are deactivated to allow unburned gas to escape before the next trial. Post-Purge After all ignition cycles are complete, the control will enter post-purge. The 25/29 combustion fan will remain on to allow unburned gas to escape. After post-purge (90+ option) is complete, the combustion fan will turn off. Lockout Time The period of time between initiation of gas flow and the action to shut off the gas 300 flow in the event of failure to establish proof of the supervised ignition source or the supervised main burner flame. einitiating the lighting sequence requires a manual operation if ignition is required before Auto reset. Heat Delay to Fan On Timing to allow the heat to build up in the plenum before turning on the fan. 30 Heat Delay to Fan Off* Timing to allow the fan to run after the call for heat ends. This allows residual heat 90/120/150 to be removed from the heat exchanger and distributed to the conditioned space. Cool Delay to Fan On Timing to allow the cooling coils to cool off before turning on the fan. 5 Cool Delay to Fan Off Timing to allow the fan to run after the call for cool ends. This allows residual 60 cooling capacity to be removed from the cooling coils and distributed to the conditioned space. Auto eset If shutoff occurs, the control delays for a specific recycle delay period before 60 minutes beginning another trial for ignition (models with retries only). * These times will vary depending on option switch position. See INSTALLATION section for further information. 2
INSTALLATION ANIN FIE HAZAD Do not exceed the specified voltage. Protect the control from direct contact with water (dripping, spraying, rain, etc.). Label all wires before disconnection when servicing controls. iring errors can cause improper and dangerous operation. oute and secure wiring away from flame. SHOCK HAZAD Disconnect electric power before servicing. Ensure proper earth grounding of appliance. Ensure proper connection of line neutral and line hot wires. EXPLOSION HAZAD Shut off main gas to appliance until installation is complete. CAUTION Do not short out terminals on gas valve or primary control. Short or incorrect wiring may damage the thermostat. MOUNTIN AND IIN All wiring should be installed according to local and national electrical codes and ordinances. The control must be secured to an area that will experience a minimum of vibration and remain below the maximum ambient temperature rating of 175 F. The control is approved for minimum ambient temperatures of -40 F. Any orientation is acceptable. efer to the wiring diagram and wiring table when connecting the 50T35 control to other components of the system. UL approved, 105 C rated 18 gauge, stranded, 2 /64 thick insulation wire is recommended for all low voltage safety circuit connections. UL approved 105 C rated 16 gauge min., stranded, 4 /64 thick insulation wire is recommended for all line voltage connections. Follow the appliance manufacturer s recommended installation or service instructions. The 50T35 has only one serviceable part an automotive type fuse, which protects the low voltage transformer from damage if its output is short-circuited. If the fuse has opened up, remove whatever caused the short circuit and replace the fuse with the same type 3 Amp automotive fuse. If the control does not operate correctly after replacing the fuse, replace the entire 50T35 control. There are no other user serviceable parts. emove both access panels. For MP & MPV series units, cut the white jumper wire between pins 4 & 7 of the 9 pin connector. For MPN & MN series units, DO NOT cut the white jumper wire. emove the edgecard connector and other wires from the existing module. Discard the thermostat wires removed from the board (, & ). emove the existing HSI module. Care should be exercised to avoid damage to the nylon standoffs. Install the 50T35-743 module. econnect the edgecard connector making sure of good contact. Push the 9 pin connector into the HSI module. It can go in only one way. DO NOT force. econnect the supplied thermostat wires. emove the red wire from the 24 volt side of the secondary side of the transformer and discard. emove the blue ground wire from the transformer. DO NOT discard. emove the blue wire from the transformer and discard. Connect the red wire from the 9 pin connector to "24 volt" of the secondary side of the transformer. Connect the blue wire from the 9 pin connector to "Common" terminal of the secondary side of the transformer. This wire has a piggy back terminal. Connect the blue ground wire, which was previously removed, also to the "Common" terminal of the transformer. eplace the access panels. estore gas and electrical power to the furnace. Verify the sequence of operation as noted in the furnace manufacturers Installation & Operating Instructions. Black 115v. Supply hite 24 v. ed Com. Blue ND. Blue 3 TANSFOME
INSTALLATION SELECTIN THE BLOE OFF DELAY In the heating mode, the blower off delay can be selected to obtain a 90, 120 or 150 seconds period. This can be accomplished by changing the position of a plastic jumper located on the ignition control. See the drawing below for the location of this jumper. BLOE TIME OFF JUMPE The control is factory set to give a (150) second blower off delay. See drawing below for the jumper position for all available settings: TIN Notes: If the jumper is removed, the control will default to a (150) second blower off delay in the heating mode. The blower on time in the heating mode is (30) seconds and is non-adjustable. The blower on time in the cooling mode is (5) seconds and is non-adjustable. The blower off delay in the cooling mode is (60) seconds and is non-adjustable. Caution is to be exercised not to bend the metal pins when changing the time delay from the factory setting. JUMPE SET JUMPE SET JUMPE SET FO 90 SEC. FO 120 SEC. FO 150 SEC. DIANOSTIC FEATUES The 50T35-743 control continuously monitors its own operation and the operation of the system. If a fault occurs, the LED will indicate a fault code as shown below. If the fault is internal to the control, the light will stay off. In this case, the entire control should be replaced, as the control is not field-repairable. If the sensed failure is in the system (external to the control), the LED will flash in the following flash-pause sequences to indicate failure status (each flash will last approximately 0.25 seconds, and each pause will last approximately 2 seconds). Monitored LED Condition During Action Solid On Normal All Times None required 1 Flash Ignition retries Heating as Valve Off exceeded Demand Circulator Delay Off 2 Flashes PS Stuck Heating All Outputs Closed Demand Off except circ Only cool speed in response to a call for fan/cool 3 Flashes PS Stuck Heating All Outputs Open Demand Off except circ Only cool speed in response to a call for fan/cool 4 Flashes Limit Switch Heating as Valve Off Open Demand Circulator On Only Inducer On 5 Flashes Improper All Times as Valve Off Flame Circulator On Inducer On apid Improper Power-up as Valve Off Flashing Polarity Circulator Off Twinning All other as Valve Off Fault times Circulator Off Off Internal error All Times as Valve Off detected Circulator Off 4
HOT (LINE) TYPICAL SYSTEM IIN DIAAM 120 VAC NEUTAL (LINE) 24 VAC CLASS II TANSFOME TH 24 VAC T 50T35-743 PI TNS BLK FLAME SENSO POBE M1 M2 FS PESSUE SITCH (N. O.) HIH LIMIT (N. C.) 90+1 PSO TH 90+0 LIMO T V PSI LIMI AS VALVE TIN* TIN* THEMOSTAT 50T35-743 in other furnace(s) TINNIN APPLICATIONS ONLY NEUTAL INDUCE HSI EAC IND HUM INITO ELECTONIC AI CLEANE HUMIDIFIE HEAT COOL CICULATO BLOE LEEND Low Voltage (24 VAC) Line Voltage (120 VAC) N. C. = Normally closed switch N. O. = Normally open switch * The twinning feature is available only on models with six screw terminals; one of these terminals will be designated TIN. All 50T35-743 controls used in twinning applications must have the TIN terminal. 5
TYPICAL SYSTEM IIN TABLE 50T35 TEMINAL TIN* 90+1 PSO TH 90+0 LIMO T V PSI LIMO IND HSI EAC HUM COOL HEAT NEUTAL (4 terminals) FS M1 M2 PI TNS BLK TEMINAL TYPE 3/16" spade terminals 3/16" spade terminals 9-pin connector & harness or edge connector s SYSTEM COMPONENT CONNECTION low voltage thermostat terminal (or equivalent) low voltage thermostat terminal (or equivalent) low voltage thermostat terminal (or equivalent) one wire twinning terminal option jumper for MP and MPV Series Units pressure switch OUTPUT 24 VAC transformer (low voltage HIH side) option jumper for MP and MPV Series Units high limit OUTPUT 24 VAC transformer (low voltage COMMON side) gas valve pressure switch INPUT high limit INPUT inducer HOT side ignitor HOT side electronic air cleaner HOT side humidifier HOT side circulator blower COOL SPEED terminal circulator blower HEAT SPEED terminal input voltage (120 VAC) NEUTAL side and NEUTAL line connections flame sensor probe park park 24 VAC transformer line voltage HOT side 24 VAC transformer line voltage NEUTAL side input voltage (120 VAC) HOT side * All 50T35-743 controls used in twinning applications must have the TIN terminal. Maximum recommended flame probe wire length is 36 inches. hite-odgers is a division of Emerson Electric Co. The Emerson logo is a trademark and service mark of Emerson Electric Co. St. Louis, Missouri www.white-rodgers.com